1. Field of the Invention
The present invention relates generally to systems and methods which are used in spectrophotochemical analysis. More particularly, the present invention relates to spectrophotometric instruments and methods which are used to analyze fluids in a wide variety of laboratories including clinical laboratories and other healthcare facilities.
2. Description of the Related Art
Clinical chemistry involves the qualitative and quantitative analyses of body fluids, such as blood, urine, spinal fluid and other materials. Clinical chemistry encompasses multiple specialty testing areas including coagulation, hematology, immunochemistry, as well as chemistry. The test results derived from such analyses are used by physicians and other healthcare professionals to diagnose, monitor and treat diseases. The analysis protocols, instrumentation and other equipment utilized in clinical laboratory testing must be capable of providing accurate and repeatable test results. In addition, it is desirable that the procedures and instrumentation be simple and efficient. The testing equipment and procedures should be versatile enough that they can be used in healthcare locations where relatively few samples are tested as well as in larger clinical laboratories where the number of samples being tested on a daily basis is quite large.
A wide variety of analysis protocols are based on spectrophotometric analysis of the fluid being tested or the reaction product(s) of the fluid and one or more reagents. In a typical spectrophotometric analysis, the test fluid is introduced into a cuvette and radiation at one or more selected wavelengths is passed therethrough. The radiation absorption properties of the fluid are measured and may be used in both quantitative and qualitative determinations. In order to be useful in a clinical setting, an analytical system must be able to carry out spectrophotometric determinations.
Another consideration in designing analytical equipment for use by healthcare personnel is the amount of sample available for testing. In many situations, the amount of blood or other bodily fluid available is relatively small. Accordingly, there has been a trend in clinical chemistry to develop analytical systems which are capable of conducting numerous different chemical analyses on relatively small amounts of sample. In general, the goal has been to develop clinical analytical systems which provide the maximum number of medical tests utilizing the minimum amount of sample.
In achieving the above goals, a multitude of different analytical procedures and approaches have been investigated. In one approach, instruments have been developed which have a single sample introduction site. The equipment is designed so that the sample is split and routed to various locations within the system where multiple chemical analyses take place. Other systems do not include internal sample splitting devices and rely on the clinical chemist to separate the sample into small aliquots which are introduced into various instruments which are capable of conducting a maximum of only a few chemical analyses at one time.
There is a continuing need to develop and provide clinical chemistry equipment which is not only accurate, but versatile enough to meet the demands of modem medicine. The equipment should be simple enough to be used by not only highly-skilled laboratory technicians, but also by other healthcare personnel who may be required to conduct laboratory tests from time to time. The equipment and procedures should be versatile enough so that they can be utilized in clinical laboratories which analyze thousands of samples daily, while at the same time being adaptable to doctors' offices, home healthcare agencies and nursing homes where the number of tests being conducted is not as great. In addition, the equipment should be versatile enough to be useful in conducting a wide variety of blood analyses which are presently being routinely utilized. The equipment should also be adaptable to conducting blood or other bodily fluid tests which will be developed in the future.